Mitigative effects of epigallocatechin gallate in terms of diminishing apoptosis and oxidative stress generated by the combination of lead and amyloid peptides in human neuronal cells

Abstract

Environmental exposure to lead (Pb) is reported to associate with the development of Alzheimer's disease, where the formation of β-amyloid peptides (APs) of (1-40), (1-42), and (25-35) is considered as the major risk factor. In this context, we aimed at investigating the effect of epigallocatechin gallate (EGCG), a major flavonoid polyphenol available in green tea, in mitigating the individual and combined toxicity generated by Pb and β-APs in terms of oxidative stress and apoptosis in human neuronal cells. SH-SY5Y cells were exposed to Pb and β-APs of (1-40) and (25-35) individually and in different combinations in the presence and absence of EGCG. The results indicated that EGCG mitigated both Pb- and β-AP-induced oxidative stress in scavenging reactive oxygen species and apoptosis by improving the expression levels of Bax and bcl2 and inhibiting annexin V and caspase-3. Thus, our study shows that EGCG protects SH-SY5Y cells against the cytotoxicity induced by Pb and β-APs by decreasing oxidative stress and inhibiting apoptosis.

Keywords: apoptosis; human brain cells; in vitro; lead; β-amyloid peptides.